Full Outline of UnResponsiveness (FOUR) Scale: a Multicenter Validation Study of the Psychometric Properties of the Approved Russian Version

Assessment of the individual level of consciousness on admission of a patient with brain injury to the intensive care unit (ICU) is a priority task and a mandatory step in the overall assessment of neurological status. The Full Outline of UnResponsiveness (FOUR) scale, developed at the Mayo Clinic (USA) in 2005, is a widely used tool for comprehensive assessment of patients with altered state of consciousness. The lack of a validated Russian-language version of the FOUR scale has hindered its widespread use in clinical practice. Therefore, the official Russian version of the FOUR scale was developed and adapted for use in Russia after the first stage of the validation study (linguistic and cultural adaptation).

Aim. To evaluate the psychometric properties of the Russian version of the FOUR scale for comprehensive assessment of patients in altered state of consciousness.

Materials and Methods. As part of a prospective multicenter validation study, the psychometric properties of the scale (reliability, validity, and sensitivity) were evaluated in a group of 171 adult patients with altered conscious state of various etiologies, such as ischemic and hemorrhagic stroke, neuroinflammatory conditions, and traumatic brain injury. Patients’ responses were assessed on the first day of ICU stay and 2-3 days later by two ICU neurologists with at least three years of experience.

Results. High levels of validity and reliability were obtained for the Russian version of the FOUR scale for comprehensive assessment of unresponsive patients, including Spearman’s rank correlation coefficient r=0.99 (P<0.0001), Cohen’s κ=0.77 (P<0.001), Cronbach’s α=0.87 (P<0.0001). Regarding the sensitivity of the FOUR scale, no significant changes were found after comprehensive assessment of unresponsive patients on day 1 in the ICU and 2-3 days later (Wilcoxon test, P=0.906). There was a good correlation between the FOUR and Glasgow Coma Scale scores used to assess patients with altered state of consciousness, confirming the validity of the test with r=0.91 (P<0.0001).

Conclusion. The Russian version of the FOUR scale for comprehensive assessment of unresponsive patients is a valid, reliable, and sensitive clinical tool. Sufficiently verified level of psychometric properties allows its authorized use in Russia and other Russian-speaking countries. The scale is available for download via QR code and at the website of the International Scales and Questionnaires Validation Group at the Scientific Center of Neurology.

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